#!/usr/bin/env python
#coding:utf8
# a = None
# if not a:
#     print 'a is empty'
# b = []
# if not b:
#     print 'b is empty'
# c = {}
# if not c:
#     print 'c is empty'
# d = ''
# if not d:
#     print 'd is empty'

# if a is None:
#     print 'a is none'
# if b is None:
#     print 'b is none'
# if c is None:
#     print 'c is none'
# if d is '':
#     print 'd is none'

# e = {0:{}}
# if not e:
#     print 'e is empty'
# if e is None:
    # print 'e is empty'

cols = ['1','2','3']
print cols[:1]
print [c for c in cols]
print [cols[0] if cols[0]=='1' else (c) for c in cols]
print [x*x for x in range(10) if x % 3 == 0]
print [cols[1] if cols[1] % 3 == 0 else x for x in range(10)]
    # c[1:] if c[0] == '#' else '.'.join(bt(c.split('.')[0]) + bt('.'.join(c.split('.')[1:]))) for c in cols


